Looking back through the history of vintage Pennsylvania license plates, it is surprising how little the design has changed over the years. Adopted in the early 1910s, the keystone symbol was a mainstay of almost every plate produced between the 1910s and 1920s.
During many of the middle decades of the 20th century, license plates featured an outline of the state around the numbers, only to return to the keystone design in 1977.
In general, vintage Pennsylvania license plates are blue and yellow and don’t change much from year to year. However, the last forty years have also seen the introduction of various special interest plates, promoting topics from historical conservation to drug awareness. These plates might make a more interesting addition to your collection.